Grinding machine



N0v;l1,1924.

G. W. FLEMING ET AL GRINDING MACHINE 2, 1921 4 Sheets-Sheet 1 Filed March ATTORNEYS.

Nov. 11, 1924- 1,515,568

G. W. FLEMING ET AL GRINDING MACHINE Filed March 2. 1921 4 Sheets-Sheet 2 I INVENTOR ATTORNEY5.

Nov. 11, 24. 1,515,568

G. W. FLEMING ET AL GRINDING MACHINE Filed March 2. 1921 4 Sheets-Sheet s 11/ 7 fif ATTORNEYZ).

Nov. 11; 1924.

G. w. FLEMING ET AL GRINDING MACHINE Filed March 3. 1

4 Sheets-Sheet 4 I NV TOR ATTORNEYfi.

GEORGE W. FLEMING AND ROBERT W. ELLINGH AM, OF SPRINGFIELD, MASSACHU- SETTS, ASSIGNORS T0 .VAN NORMAN MACHINE TOO'L COMPANY, OF SPRINGFIELD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. Y

GRINDING MACHINE.

Application filed March 2, 1921. Serial No. 449,250.

'1 0 all whom it may concern.

Be it known that we, GEORGE W. FLEM- ING and Ronnirr W. ELLINGHAM, citizens of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented new and useful Improvements in Grinding Machines, of which the following is a specification.

This invention relates to an improved grinding machine, of the general character shown and described in the Patent No. 938,- 803, granted Nov. 2, 1909," to C. E. Van Norman, and hasfor its object, more particularly, the provision of mechanism for grinding a curved surface of small radius and long straight-line axis. The present invention is adapted to a variety of uses and applications, but in the embodiment shown the mechanism is designed more particularly for the grinding of the concave surfaces of buckets or curved blades of turbine motors.

Heretofore, in grinding machines of the character having a grinding wheel mounted at the end of a rotating spindle, it has been diflicult to grind concave surfaces of comparatively small radius and of long extent, due to the fact that the grinding wheel spindle (which must of necessity have a smaller radius than that of the curved sur face to be ground) cannot be unduly lengthened without resulting in a whipping or vibrating action of the long unsupported part of the spindle, which is both detrimental to good grinding action and apt to cause breakage of the spindle.

An object of the present invention is to overcome this difficulty by mounting the grinding wheel and spindle with its axis of rotation at a slight angle to the longitudinal axis of the'surface tobe ground and during the rotation of the grinding wheel effecting a relative oscillation between said grinding wheel and the work to be ground. By thus mounting the spindle of the grinding wheel with its axis at an angle to the longitudinal axis of the concave surface to be ground, the spindle of the grinding wheel may be tapered and formed with sufiicient stock, even in a long spindle, for supporting means are also the h grinding wheel in a manner to avoid t e whipping action above referred to.

A further object of the invention is toprovide means for adjusting the length or amplitude of the oscillatory movement, and

tudinal axis.

In the embodiment shown, automatic feed mechanism is also provided to effect the cross-feed for the depth of the grinding action automatically during the operation of the machine and without further attention on t e part of the operator than to adjust said automatic feed mechanism to the depth of grinding action desired.

Other objects of the invention relate to various details of construction and improved arrangement and operation of the parts, as will be more fully set forth in the detailed description to follow.

Referring to the drawings, which illustrate the preferred embodiment of the invention,

Fig. 1 is a side elevational view of the grinding machine;

Fig. 2 is a horizontal sectional view of certain of the operating mechanisms of the machine; 7

Fig. 3 is a top plan view of the grinding head;

Fig. 4 is a top plan view of a part of the operating mechanism for the automatic cross-feed mechanism;

Fig. 5 is a side elevational view of a portion of the automatic cross-feed mechanism shown in Fig. 4;

Fig. 6 is an end view j in elevation of a Po t on of the maohlne;

v concave surface of small radius and of comparatively long longi Fig. 7 is atop plan view of the workholder or fixture for supporting the work to be ground;

Fig. 8 is aside view of the fixture shown inFig.7;

Fig. 9 1s a sectional view. taken along the line 9-9 of Fig. 7;

Fig. 10 is'a'n end shown in Fig. 7;

Fig. 11 is a sectional view taken along the view of the structure line 1111 of Fig. 7; i

Fig. 12 is a perspective view of the work to be ground;

Fig. 13 is a sectional view taken along the line 1313 of Fig. 1; 1

Fig. 14 is a sectional view taken along the line 1414 of Fig. 13; p

Fig. 15 is an end view in elevation of a portion of the machine showing a modified formof oscillating mechanism; and

Fig. 16 is a sectional view taken along the line 16--16 of Fig. 15.

In the embodiment of the invention illustrated herewith, 1 designates the base frame for supporting the operating mechanism. Slidably mounted in suitable ways upon the top of the supporting frame 1 1s a bed 2 movable longitudinally of the frame. Mounted for longitudinal adjustment upon the bed 2 is a base plate 3 adapted to be firmly secured in its adjusted positions by meansof a plurality of bolts 4. A workhead 5 has a swivel mounted upon the plate 3 and may be adjusted in various angular positions relative thereto, the degree of adjustment of which may be accurately determined by means of a graduated scale 6 formed upog the base of the work-head. In the use of the machine about to be described, however, the work-head is usually fixed with its longitudinal axis parallel to the longi-' and upon said slide 10 is mounted the grinding-wheel head 11. The grinding-wheel head 11 is horizontally adjustable to various angular positions upon the slide 10, as indicated in Fig. 3 of the drawings and is adapted to be secured in any one of its adjusted positions by means of one or more locking bolts, such as 12. The grinding-wheel spindle 13 is rotatably mounted in a bearing 14 carried by the grinding-wheel head and is provided with a drive-pulley 15 by which it may be driven through a belt 16 from a drive-pulley 17 carried by a drive-shaft 18 in suitable bearings 19 formed in the grinding-wheel, head. The shaft 18, in turn, is drlven by pulley 20 fixed to said shaft through a belt from any suitable source of power (not shown), said driving means being designed to give the spindle '13 a very rapid rotation, as is customary with grinding wheelsof this character. V

The bed 2 and the reciprocating mechanism therefor will now be described. As will be seen upon reference to Fig. 2 of the drawings, the frame 1 is provided with transverse webs 54 and 55 located adjacent opposite ends of the frame, and 'slidably mounted in bearings provided in said webs is a longitudinally-extending slide-rod 56. The slide-rod 56 has fixedly secured thereto a block 57 provided with a recess 58 for the reception of a lug 56 formed integrally with an adjusting slide-piece 58 which has a sliding fit for being clamped within a groove 57 formed in the under surface of the bed 2 so that the bed may be reciprocated with said rod 56. The adjusting slide-piece 58 extends some distance at each side of the lug 56 and may be securely clamped in any one of a plurality of adjusted positions longitu-.

dinally of said bed 2 by a suitable clamp indicated at 128. By loosening the clamp 128.

the bed 2 may be moved by hand independ ently of saidslide-rod 56. Across-head comprising a. pair of spaced transverselyextending plates 59 and 60 is fixedly secured to the slide-rod 56 and is adapted to receive between said plates a roll 61 carried with a swinging lever 36. A guide-bar 62 fixed to the frame 1 and engaging notched ends 63 of the spaced plates 59 and 60 serves to maintain said cross-head in horizontal position duringthe travel.

The mechanism for giving reciprocating movement to the cross-head 59, 60,'and connected bed 2 comprises an upright shaft 33 adjacent the upper end of which is a disk 34 provided with a heart-shaped cam groove 35. The swinging lever 36 is pivotally mounted, as at 37 to a boss 38 carried by the frame (see Fig. 4) and extends across the upper face of the disk 34, being provided intermediate its ends with a downwardly-extending roll 39 positioned within the cam groove 35Qwhereby the lever is oscillated upon rotation of the disk 34. The lever 36- is provided at opposite ends with upwardlyextending lugs 40 and 41 for rotatably supporting a worm-shaft 42 which is located above and substantially parallel with the lever 36. A slide 43 is mounted upon the lever 36 for movement longitudinally thereof and is provided with an upwardly-extending boss 44 through which the worm shaft 42 extends in threaded engagement so that by rotation of the worm shaft 42 the slide 43 may be adjusted back and forth along the lever 36. The roll 61 is carried upon the boss 44 and extends upwardly therefrom between the plates 59, 60, of the cross-head, as above described, whereby theswinging movement of the lever imparts a reciprocating movement to the cross-head and bed 2. The 'worm'shaft- 42 is connected by a universal joint 45, supplemental shaft 46, and universal joint 47 with shaft 48 suitably supported in bearings on the frame 1. The shaft '48 is provided with a spurgear 49 meshing with a spur-gear 50 carried by a parallel shaft 51 upon one end of which is fixed the hand-wheel 52 by means of which the shaft 51 may be rotated and through the connections described impart rotation to the worm shaft 42 to adjust the slide 43 longitudinally of the lever 36. The universal joint connections between the shaft 42 and shaft 48 permit the adjustment of slide 43 in all positions of the lever 36. By the adjustment of the slide 43 androll 61 toward and away from the pivot 37 of said lever 36, the extent of reciprocating movement for the bed 2 may be regulated. -When the roll 61 is adjusted to a position in line with the pivot 37, it is obvious that no reciprocation of the bed 2 will be effected by the swinging lever 36.

In order to reciprocate the bed. 2 at substantially the same rate of speed during either a long or short travel back and forth of said bed. it is desirable to drive said'cam shaft 33 through a change-speed driving mechanism so that said shaft 33 may be operated at a slower speed when the roll 61 is adjusted to give a long throw to said bed 2, and vice versa. The mechanism for driving the cam shaft 33 comprises a power shaft 22 mounted in bearings in the frame and provided adjacent one endthereof with a stepped pulley 23 which is adapted to be driven from any suitable source of power (not shown). A bevel-gear 24 is secured to the opposite end of the shaft 22 and meshes with a bevel-gear 25 carried by a shaft 26 which extends within a speed-change box 27. The speed-change box 27 houses any suitable arrangement of speed-change mechanism (not necessary to be shown in detail), whereby the rate of speed at which the reciprocating mechanism is driven may be regulated as desired by moving a speedchange lever 28 adapted to be actuated by a handle '29. A shaft 30 extending outwardly from the speed-change box 27 is driven from the shaft 26 through said speed-change mechanism. whereby it may be rotated at various adjusted speeds. A bevel-gear 31 carried by the shaft 30 meshes with a bevel-gear 32 carried by a cam-shaft 33 for driving the latter. Means are also provided to operate the cam-shaft 33 by hand, when desired, said means comprising the shaft 64 mounted in bearings ofthe main preferably effected frame 1 and having a bevel-gear 65 meshingwith a bevel-gear 66 fixed to the lower end of shaft 33. A crank 67 is releasably connected with the shaft 64 through a suitable olutch 68, whereby the cam-shaft 33 may be operated by hand when the power is off to move the bed 2 upon the frame.

' It is also desirable at times to adjust the bed 2 upon the frame relative to the reciprocating mechanism in order to change the field of reciprocating movement for the bed or to withdraw the work being ground from the grinding wheel. For this purpose, a shaft 70,is rotatably mounted in the frame 1 below the reciprocating bed and is provided with a spur-gear 71 adapted to engage a rack 72 secured to the lower surface of the bed. A hand-wheel 73 is secured to the shaft for rotating the same and thus move the bed 2. independently of the powerdriven mechanism. In moving the bed 2 by the hand-wheel 73, the clamp 128 should, of course, be loosened to disconnect the bed from the power-driven mechanism. As before stated, the adjusting slide-piece 58 and clamp 128 function to adjust the bed relative to the power-driven mechanism.

The cross-feed for bringing the grinding wheel against the work to be ground is by a feed movement of the slide 10 upon which the grinding-wheel head 11 is carried.

As previously stated, the slide 10 is mounted upon the support 9 for movement transversely. of the path of travel of the re ciprocating bed, and the slide is provided upon itsunder surface with a rack 75 lo cated in meshing engagement with a spurgear 7 6 carried by a shaft 77 suitably mounted in the support 9. A worm-gear 78 fixed to the shaft 7 7' adjacent the outer end thereof is in meshing engagement with a worm 79 carried by the shaft 80 which extends transversely of the frame and is rotatably mounted in suitable bearings 81 carried by the frame. Fixedly secured to the shaft 80 adjacent one end thereof are hand-wheel 83 and ratchet-wheel 84 for eflecting rotation 'of said shaft to feedthe slide 10 and grinding wheel supported thereby transversely of the path of travel of the reciprocating bed to bring the grinding wheel into proper engagement with the work and maintain it in proper grinding position.

The automatic feed mechanism for rotating the shaft 80 is shown more in detail in Figs. 4 and 5. Sleeved upon the shaft 80 adjacent to the bearing 81 is a hub 85 provided with oppositely-extending arms 86 and 87, the arm 87 being connected, as at 88, with a link 89 in turn, pivotally connected, as at 90, with a depending arm 91 secured to one end of a rock-shaft 92 supported in a bearing 93 carried by the frame 1. An upstanding arm pivotally which is,

radial 94 is fixed to the inner end of the rock-shaft 92 and is adapted to be rocked from a suitable part of the mechanism during the operation of the machine.

A boss 95 carried by the frame 1 projects inwardly adjacent the shaft 92 and is provided with a passage 96 within which is slidably mounted a plunger 97 arranged to bear at one end against the lever 94 and having the opposite end thereof engaged by a rounded projection 98 carried by the swinging lever 36. A coiled compression spring 99 is positioned between the side of the lever 94 opposite to that engaged by the plunger 97 and a portion of the frame 1, and tends to constantly hold the lever against the end of the plunger 97. The mechanism just described serves to rock the lever 94 together with the shaft 92 to which the lever is secured at intervals upon oscillation of the lever 36, as previously described, and thus rock the hub 85 through the connections with the arm 87, whereby the arm 86 is oscillated about the shaft 80 as a center. A boss 100 carried by the arm 87 has a pin 101 projecting outwardly therefrom, upon which is pivotally mounted a pawl 102 adapted to engage ratchet teeth 103 on the periphery of the ratchet-wheel 84, whereby the wheel84 and the shaft 80 to which the wheel is'seeured are rotated in a clockwise direction as seen in Fig. 5 of the drawings through the oscillation of the lever 36. As the shaft 80 is rotated in the manner just described, the worm 79 carried thereby engages the worm-gear 78, whereby the shaft 77 is rotated and the slide 10 fed inwardly transversely of the path of movement of the reciprocating bed.

Since the mechanism just described is adapted to feed the grinding wheel at a constant rate of speed regardless of the hardness of the material to be ground, it is desirable to provide means whereby the rate of speed with whichthe grinding wheel is fed may be varied in any desired'manner in accordance with the requirements of the particular work being ground. To provide suitable means for thus varying the rate of feed, a sleeve 104 is loosely mounted upon the shaft 80 adjacent to the sleeve 85, the sleeve 104 being provided with a segmental plate 105 extending outward radially there from and engaging the outer face of a boss 106 carried by the fame. A segmental slot 107 formed in the plate 105 is adapted to receive a c mp serew 108 threaded into the boss 106 by which means the segmental plate 105 may be held in any one of a variety of adjusted positions cireumferentially of the shaft 80. A curved plate 109 is secured to the segmental plate 105 in any suitable manner, as by screws 110, and is adapted to overlie a portion ofthe toothed periphery of the ratchet-whee1'84 so that by securing the plate 105 in proper adjusted position the the plate 105, the number of teeth opera-,

tively engaged by the pawl during each oscillation of the sleeve 85 may be diminished to any desired degree, and the amount of rotation imparted to the shaft 80 at each oscillation of the sleeve 85 may be made as small as desired to reduce the speed with which the grinding wheel is fed against the work to be ground.

A device for'automatically stopping the action of the feed mechanism at any predetermined point during the operation of the machine is provided, which comprises a disk 112 loosely mounted upon the shaft 80 next to the ratchet-wheel 84 and provided with a peripheral shoulder 113 adapted to be engaged by the head 114 of a clamp-bolt 115 carried by the ratchet-wheel 84, whereby the disk 112 may be firmly secured to the ratchet-wheel in various adjusted positions and carried therewith. An arm 117 extends radially outward from the disk 112 to a point adjacent the periphery of the ratchetwheel, where it is provided with a throwout plate '118 projecting over the periphery of theratehet-wheel and adapted to be carriedbeneath the pawl 102.. It will be understood that the throw-out plate 118 may be positioned at different points on the ratchet-wheel 84, depending upon the extent of cross-feed desired, sothat at the proper time for stopping said cross-feed, the plate 118 will arrive beneath the pawl 102 and throw it out of active engagement with the ratchet. In this way, although the machine may be continued in operation, no further grinding action will take place. It there fore becomes unnecessary for the operator to stop the mechanism from time to time to note the progress of the grinding operation, since the grinding-wheel will not be fed further against the work after the desired depth of grinding action has been obtained.

A friction-brake 120 secured to an arm 105 is adapted to bear against one face of the ratchet-wheel 84 to prevent rotation of the same except when positivelr actuated by the pawl previously described or manually through the hand-wheel 83. A pin 121 projects outwardly from the pawl 102 and provides a convenient means for throwing the pawl out of engagement with ratchetwheel 84 when desired, as, for example, when it is desired to manually adjust the position of the grinding wheel by rotating the ratchet-wheel in a counterclockwise direction, as seen in Fig. 5, through the handwhe l 83.

The mechanism for securing relative oscillatory movement between the work to be ground and the grinding wheel during the grinding operation, is in the present embodiment of the invention effected by oscillating the work-supporting member during the grinding operation, although it will be understood that this relative movement of the work and grinding wheel may be effected with equal readiness by giving the grindingwheel support oscillatory movement One form of mechanism for oscillating the work is shown in Figs. 1, 2, and 6. Referring more particularly to these views, an auxiliary frame 124, secured to the supporting frame 1 in any desired manner, extends from the end thereof as shown and carries an arched supporting member 129. A bearing 130 for a rotatable sleeve 131 is formed in the member 129, and the sleeve 131 has a squared passage extending therethrough in which is slidably and non-rotatably mounted a squaredshaft 132. The sleeve 131 is provided with a collar 144 which may be secured to one end thereof to bear against one side of the bearing 130, while a crank-disk 134 secured to the other end of the sleeve bears against the opposite side of the bearing 130 to prevent the sleeve from sliding longitudinally while permitting the sleeve to rotate freely in the bearing. One end of the shaft 132 is connected with the end of the work support or shaft 7 bya universal joint 133, and the telescopic connection between the square shaft 132 and the oscillating sleeve 131 permits the work support 7 to be oscillated during the reciprocation of the work head 5 and bed 2. The crank-disk 134 secured to the sleeve 131 is provided with a radial slot 135 wherein may be adjustably secured a crank-pin 125. i

A shaft 136 is rotatably mounted in bear- "ings 137 carried by the frame 124 and has secured thereto a drive-pulley 138 by which it may be driven from any suitable source of power. A crank-disk 139 of smaller radius than the crank-disk 134 is keyed or otherwise fixedly secured to the shaft 136 and is provided with a radial groove 140 within which may be adjustably secured a crankpin 141. A connecting-rod 142 connects the crank-pins 125 and 141, whereby the larger crank-disk 134 will be oscillated by the rotation ofthe smaller crank-disk 139. The crank-pins 125 and 141, being adjustable radially of the disks 134 and 139, may be properly positioned to vary the extent of angular movement imparted to the sleeve 131-in other words, to vary the amplitude of the oscillatory movement-whereby the work support may be oscillated the desired degree for grin-ding a curved surface of the desired extent. It will be seen that the mech is oscillated throug the same as it is reciprocated longitudinally of the frame by reason of the reciprocation of the bed 2. As the squared shaft 132 is slidably mounted in the sleeve 131, it will readily slide therein as the work-carrying head reciprocates, while the oscillating mechanism attached to the sleeve imparts the proper oscillation to said shaft.

Another form of oscillating mechanism which may be employed advantageously for oscillating the work support is shown in Figs. 15 and 16. As shown in these views, the arched supporting member 129 is carried by the auxiliary frame 124, as previously described. A bearing 183 for a rotatable sleeve 184 is formed in the member 129, and the sleeve 184 has a squared passage extending therethrough in which is slidably and non-rotatably mounted the squared shaft 132. The sleeve is provided with a collar 185 secured thereto adjacent one end thereof by any suitable means, such as a key 186, to bear against one side of the bearing 183, while a nut 187 site end of the sleeve to bear against the op posite side of the bearing 183. A small gear 187 is secured to the collar 185 in any desired manner. for adjustment circumferentially thereof. The means for permitting adjustment of the gear relative to the collar comprises, in the embodiment of the invention shown herewith, a plurality of segmental slots 188 formed in the gear, in which are positioned clamp-screws 189 threaded into the collar to clamp the gear firmly thereto in any desired angular position, and permit the adjustment of the same, as circumstances having a radial slot 191 formed on one face thereof, in which is adjustably mounted a crank-pin 192. A segmental gear 193 is pivotally mounted upon a shaft 194 suitably supported by the frame and meshes with the gear 187. The segmental gear 193 is provided with a crank-pin 195 suitably positioned upon one face thereof, and a connecting-rod 196 connects the crank-pins 192 and 195, whereby the segmental gear may be oscillated upon rotation of the crank-disk 190. It will be seen that the crank-pin 192 may be adjusted radially to vary the angular throw imparted to the segmental gear 193, and by suitably adjusting the gear 187 upon the collar 184 the field of oscillation of the work-holding member relative to the grinding wheel may be varied as desired. As in the form previously described, the squared shaft 132 is slidably mounted in the sleeve 184 to readily slide therein as the workcarrying head reci rocates, while the shaft the mechanism just described.

The field of oscillation for the work support relatively to the grinding wheel may be varied to a limited degree by the adjustment in .the bar 152 and is adapted when in posiof the clamp-screws 188 in the segmental slots 189, while unlimited variations of the field of oscillationwhat is, within any are of the entire circumference of rotation of the work supportmay be obtained by completely disconnecting the gear 187 from the collar 185 and the gear segment 193, turn ng the work support to the field of oscillation desired and then reconnecting the gear 187.

A suitable fixture that may be employed for holding the workupon the work support in suitable position to be operated u on by the grinding wheel is shown in Figs. to 11, inclusive, of the drawings and Wlll now be described. The work-holder comprises a plate 151 secured in any desired manner to the collar 7 of the support 7, and a bar 152 projecting from the plate substantially parallel with the axis of the support 7. The bar 152 is'slotted, as at 153, throughout a portion of its extent for receiving therein the work to be ground which, in the present instance, is one of the buckets A of a turbinewheel and which is shown in detail in Fig. 12 of the drawings.

The bucket A, as shown in Fig. 12 of the drawings, is provided with a squared shank a and a blade portion 5 one face of which has a concave surface 0 to be ground, said concave surface having a substantially straight line axis of curvature throughout its length. -A reduced end d is formed as a continuation of the blade I).

A gate 154 is pivoted to the bar 152, as at 155, and is provided with a slidable latch 156. normal 1y forced outwardly by a coiled spring 157, *a hereby it will engage a lip 158 carried by closed position. The latch 156 is provided with a handle 159 by which it may be forced" -backwardly against the tension of the-spring 157 to release the latch from engagement with the lip 158. A leaf-spring 160 is carried by thegate in position to bear against the bucket A when the same is properly positioned in the holder, the spring being adjustably supported upon the gate by means of a bolt161 positioned in a'slot 162 formed in the ate andadapted to be secured in any desire position therein by means of a locknut 163.

'Slidably mounted upon the bar 152 is an abutting member 164 which comprises a portion 165 of reduced width adapted to lie in the slot 153. A thumb-screw 166 projects through the member 164and is threaded into a block 167, whereby the block and abutting member may be clamped to the bar 152 in any position longitudinally thereof. The abutting member 164 is provided with a shoulder 168 adapted-to abut against the shank of the bucket A when the bucket is in position. The reduced. portion d of the bucket projects forwardly of the slot formed the bar 152 to holdthe gate in,

invention the work-holder inserted with the reduced end d properly enga ing the ledge'170 and the shank portion a earingagainst the shoulder 168 of the abutting member. .The spring 160 is then properly adjusted upon the gate 154 to suitably bear against the bucket and the gate is then closed, whereupon the spring 160 closely engages the bucket and holds the same yieldingly and firmly against the ledge 170 and the shoulder 168. The member 164 being properly .clamped in position, the bucket is securely held against longitudinal movement relative to the holding member and is securely locked in position for grinding the concave surface a. When the curved surface has been properly ground, it is necessary only to release the latch 156, when the bucket may be removed and another placed in position for grinding. I

The relative position of the work A and the tapered grinding-wheel 180 is'illustrated in Figs. 13 and 14 of the drawings, wherein it will be seen that the taper of the grinding-wheel 180 is approximately the same as the angle of inclination of the grindingwheel spindle to the axis of curvature of the surface to be ground, whereby the tapered grinding-wheel bears against the surface to be ground throughout its length, as shown particularly in Fig. 13. The direction of oscillation of the work A relative to the grinding-wheel is more particularly shown in Fig. 14, .wherein it will-be seen that the relative oscillation between the work and the grindingwheel is such as to bring all parts of the surface to be ground into tangential relation to the surface of the grinding-wheel and thus secureproper and uniform grinding of the concave surface. The smaller end of the tapered grinding-wheel having a smaller curve than the larger end thereof, serves during the reciprocation and oscillation of the work to produce a lapping action of the grinding operation, which results in a highly polished and smoothly finished surface of the work being ground.

While in the present embodiment of the is shown as mounted upon the reciprocating bed for effecting the relative reciprocatory movement between the, work to be ground and the grinding-wheel, it is obvious that this same movement might be accomplished in other ways, as, for instance, by mounting the grinding-wheel head on the reciprocating bed 2 and maintaining the work-head in station- Ill ary osition. Various other chan es in the details and arrangement of parts s own may likewise be made without departing from the essential and novel character of the invention as hereinafter claimed in its broad aspect.

What we claim is- 1. In a grinding machine, means for grinding a cylindrical surface comprising, a support for the work to be ground, a rotating grinding wheel, means for effecting relative reciprocatory movement between the grinding wheel and the work in a; direction along the axis of the cylindrical surface being wheel and the work, the axis of said oscillatory movement being parallel to the path of said reciprocatory movement.

3. In a grinding machine, means for grinding a cylindrical surface comprising, a rotating grinding wheel having a radius not greater than the radius of the cylindrical surface to be ground, means for supporting the work in contact with the grinding wheel, and power operated means for automatically effecting a combined reciprocatory and oscillatory movement between the grinding wheel and the work while said wheel and work are in contact.

4. In a grinding-machine, means for grinding a cylindrical surface, comprising, a support for the work to be ground, a rotating grinding-wheel, power-operated means for automatically effecting a combined reciprocatory and oscillatory movement between said grinding-wheel and work to be ground, the rotational axis of the grinding wheel being in the same plane as the axis of said oscillatory movement, and means for adjusting said grinding-wheel to set its axis at an angle to said axis of oscillatory movement. 1

5. In a grinding-machine, means for grinding a cylindrical surface, comprising,

a'reciprocatory support for the work to be ground, means for reciprocating the work support, a rotating grinding-wheel, and means for effecting relative oscillation between said support and grinding-wheel during the reciprocatory movement of said suport. P 6. In a grinding machine, means for grinding a cylindrical surface comprising,

' a support for the work to be ground, a rotating grinding wheel, means for effecting relative reciprocatory movement between the grinding wheel and the work in a direction along the axis of the cylindrical surface being ground, and means actin during said reciprocatory movement for ei ecting a relative oscillatory movement between the grinding wheel and the work to be ground, the rotational axis of the grinding wheel being in'a common plane with and at an angle to the axis of said oscillatory movement.

7. In a grinding-machine, means 1 for grinding a concave cylindrical surface, comprising, a support for the work to be ground, a rotating grinding-wheel, means for effecting relative reciprocatory movement between the grinding wheel and the work in a direction along the axis of the cylindrical surface being ground, and means acting during said reciprocatory movement for effecting a relative oscillatory movement between the grinding wheel and the work to be ground, the rotational axis of the grinding wheel being disposed at an angle to the direction of said reciprocatory movement.

8. In a grinding-machine, means for grinding a cylindrical surface, comprising, a support for the work to be ground, a rotating grinding-wheel having a radius not greater than the radius of the cylindrical surface to be ground, and power-operated means for automatically effecting a combined reciprocatory and oscillatory movement between said grinding-wheel and work to be ground, the direction of said reciprocatory movement being parallel to the axis of sald oscillatory movement.

9. In a grinding-machine, means for grinding a cylindrical surface, comprising, a support for the work to be ground, a rotating grinding-wheel, and means for effecting a combined reciprocatory and oscillatory movement between said grindingwheel and work to be ground, the direction of said reciprocatory movement being parallel to the axis of said oscillatory movement,

and the axis of rotation of said grindingwheel being in a common plane with and at an angle to the axis of said oscillatory movement.

10. In a grinding-machine for grinding a cylindrical surface, a support for the work to be ground, a rotating grinding-wheel having a tapered grinding surface for contact with the work to be ground, means for effecting relative reciprocatory movement between said grinding-wheel and the work in a direction along the axis of the cylindrical surface being ground, and means acting during said reciprocatory movement for effecting a relative oscillatory movement between the grinding wheel and the work.

11. In a grinding-machine for grinding a cylindrical surface, a support for the work to be ground, a rotating grinding-wheel having a tapered grinding surface for contact with the Work to be ground, and means for effecting a combined reciprocatory and oscillatory movement between said grindingwheel and work to be ground, the axis of rotation of said grinding-wheel beingat such'an angle tothe direction of said reciprocatory movement that the working surface of said tapered grinding-wheel is substantially parallel to said direction of reciprocatory movement.

12. In a grinding-machine for grinding concave cylindrical surfaces of comparatively small radius and long extent, a support for the work to be ground, a rotating grinding-wheel supported by a tapered spindle and having a tapered grinding surface for contact with the work to be ground, and means for effecting a combined reciprocatory and oscillatory movement between said grinding-wheel and work to be ground, said reciprocatory movement being in'a direction along the axis of the cylindrical surface being ground and said spindle being disposed at an acute angle to the direction of said reciprocatory movement to avoid possible contact between the cylindrical surface bein ground and the tapered surface of the spin e.

-13. In a grinding-machine for grinding a cylindrical surface, a support for the work to be ground, a rotating grinding-wheel, and power-driven means for effecting relative reciprocatory movement between said grinding-wheel and work to be ground, in a direction along the axis of the cylindrical surface being ground, means acting during said reciprocatory movementfor effecting a relative oscillatory movement between the grinding wheel and the work, and means operated by said. power-driven means for automatically effecting a feed of said grinding-wheel against the work to be ground during the operation of said machine.

14. In a grinding-machine, a support for the work to be ground, a tapered rindingwheel, means for rotating said grindingwheel, power-driven means for effecting relative reciprocatory movement between said grinding-wheel and work to be ground, in a direction along the axis of the cylindrical surface being ground, means acting during said reciprocatory movement for effecting a relative oscillatory movement between the grinding wheel and the work, and means operated by said oWer-driven means for automatically effectlng the feed of said grindingwheel against the work to be ground during the operation of said machine, with the Working surface of said tapered grindingwheel substantially parallel to the direction of said reciprocatory movement.

15. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, means for efiecting relative reciprocation in a straight path between said grinding-wheel and work, said grindin -wheel having its axis of rotation arrange at an acute angle to said ath of reciprocation, and means for effecting relative oscillation between said support and grinding-wheel.

16. In a grindlng-machine, a support for the work to be ground, a rotating grindingwhecl, means for effecting relative reciprocation In a straight path between said grinding- Wheel and work, said grinding-Wheel havlng its axis of rotation arranged at an acute angle tosaid ath of reciprocation, and means for effecting relative oscillation between said support and grinding-wheel about an axis of oscillation parallel to said path of reciprocation.

17 In a grinding-machine, means for grinding a concave cylindrical surface, comprlsing, a support for the work to be ground, a rotating grinding-wheel, and means for effecting re ative oscillation between said support and grinding-wheel about an axis inclined at an acute angle to the axis of rotation of said grinding-wheel.

18. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, and means for effecting relative oscillation between said support and grindingwheel about an axis inclined at an acute angle to the axis of rotation of said grinding-wheel, the radius of. oscillation'being greater than the radius of said grinding wheel.

19. In a grinding-machine, a member mounted upon a reciprocating carriage and adapted to support work to be ground, a rotating grinding-Wheel, and means for oscillating said supporting member about an axis at an acute angle to the axis of rotation of said grinding-wheel.

20. In a grmding-machine, means for grinding a concave cylindrical surface, comprising, a member for supporting work to be ground, a grinding-wheel, and means for effecting relative rotary and oscillatory movements of said work-supporting member and grindin -wheel about axes arranged at. an acute ang e to each other.

21. In a grinding-machine, a shaft mounted upon a reciprocating carriage and adapted to support work to be ground, a grindin- -wheel mounted for rotation about an axlsinclined to the axis of said shaft, and

23. In a grinding-machine, a shaft mounted upon a reciprocating carriage and adapted to support work to be ground, a grinding-wheel mounted for rotation about an axis inclined to the axis of said shaft, and power-driven means for automatically reciprocating said carriage and oscillating said shaft during the grinding operation, the direction of reciprocation being parallel to the axis of oscillation.

24. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, means for effecting a relative reciprocation in a straight path between said grinding-wheel and said work support, and means for oscillating said Work support during said reciprocation comprising a rotating crank member, an oscillating member and a connecting link.

25. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, means for effecting a relative reciprocation in a straight path between said grinding-wheel and said work support, and means operating simultaneously with said first named means for oscillating said work support comprising a rotating crank member, an oscillating member and a connecting link, and means for adjustably connecting said oscillating member to said work support to vary the field of oscillation of said work support.

26. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, means operative durin the grinding operation for effecting a re ative reciprocation in a straight path between said grinding-wheel and said work support, and means for oscillating said work support comprising a rotating crank member, an oscillating gear segment, a link connecting said rotating crank with said gear segment and a gear connected to said work support and operated from said gear segment.

27. In a grinding-machine, a support for the work to be ground, a rotating grindingwheel, means for effecting a relative reciprocation in a straight path between said grinding-wheel and said work support during the grinding operation, and means for oscillating said work support comprising a rotating crank member, an oscillating gear segment, and a gear operated from said gear segment and adjustably connected to said gear segment to vary the field of oscillation of said work support.

28. In a grinding-machine, in combination, a frame, a reciprocating work head or said frame, a work support mounted for oscillation in said work head, a grindin wheel head on said frame, a rotating grin ing-wheel mounted in said grinding-wheel head with its axis of rotation at an acute angle to the direction of reciprocation of said work head, and means for oscillating said work support.

29. In a grinding-machine, in combination, a frame, a reciprocating work head on said frame, a work support mounted for oscillation in said work head, a grindingwheel head on said frame, a rotating grinding-wheel mounted in said grinding-wheel head with its axis of rotation at an acute angle to the direction of reciprocation of said work head, oscillating means on said frame, said work support havin a shaft telescopically connected with sai oscillating means so as to be oscillated during the reciprocation of said work head.

In testimony whereof we have aflixed our signatures.

GEORGE W. FLEMING. ROBERT W. ELLINGHAM. 

